Method of manufacturing artificial threads or filaments



- tive atmosphere.

Patented Aug. 1933 METHOD OF MANUFACTURING ARTIFICIAL THREADS on FILAMENTS Reginald William Payne and Robert Pierce Roberts, Spondon near Derby; England, assigners to Celanese Corporation of America, a

Corporation of Delaware No "Drawing. Original application December .12;

1928, Serial No. 325,480, and in Great Britain December 23, 1927. Divided and this application February 27, 1930. Serial No. 431,965

4 Claims. (Cl. 18--54.)

This invention relates to the manufacture of artificial filaments or threads from solutions of cellulose acetate or other esters or ethers of cellulose by the dry spinning or evaporative method of formation and is a division of application Serial No. 325,480, filed December 12, 1928.

In the spinning of such artificial threads or filaments by the dry spinning or evaporative method of formation, solutions of cellulose acetate or other esters or ethers of cellulose in volatile solvents are spun into an evaporative atmosphere (usually into a current of heated air) the threads or filaments so formed being continuously wound up, with or without twisting, on apparatus situated within or outside the evapora- The threads orfilaments heretofore produced by such method of spinning have been lustrous in character and have found successful application as artificial silk, artificia horse hair and the like.

The object of the present invention is to produce threads or filaments presenting reduced lustre and more particularly threads or filaments presenting a dull, niatt 'or lustreless appearance, or of considerably reduced lustre.

For this purpose, according to the invention, we employ solutions of cellulose'derivatives in volatile solvents and containing one or more organic precipitants for the cellulose derivative and we perform the spinning of said solutions by the dry or evaporative method under such conditions that the organic precipitant or precipitants exert a precipitating action on the filaments in the natal state of the filaments.

In performing the invention we may extrude said solutions into evaporativeatmospheres such as air or into evaporative atmospheres containing one or more of the organic precipitants.

In performing the invention we may employ as the precipitant any organic substance or substances capable of precipitating the cellulose ester or ether from its solution in the volatile solvent employed. Thus, for instance, we may employ alcohols (for instance, ethyl alcohol, cyclohexanol) hydrocarbons (e. g. benzene, xylene, petrol, petroleum ether), or esters '(e. g; butyl propionate), or ethers (e. g. propyl ether), but it will of course be understood that the choice of precipitant will depend upon the solubility characteristics of the cellulose ester or ether employed and on the relative boiling points of the volatile solvents and precipitants. According to one form of execution of the invention we may extrude into a heated metier casing or spinning cell, through which a current of air is caused to pass, a solution of cellulose acetate or other ester or ether of cellulose containing one or more of the precipitants. In such form of execution the quantity of precipitant will vary according toits' boiling point and its precipitating power-on the solution of the cellulose ester or ether employed and with the spinning conditions and the result it is desired to achieve. Ingeneral, quantities of precipitant of Example Highly satisfactory threads or yarns presenting reduced lustre maybe-produced by extruding any of the following solutions into an evaporative atmosphere of air heated to a temperature between 40 and 80 C., for instance, downwards into a suitably heated metier casing or spinning cell (such for instance as described in U. S. Patents Nos. 1,602,125, 1,541,104 and 1,731,317) through which a current of air is caused to pass in an upward or downward direction.

By varying the temperature of the heated air the above solutions will yield filaments showing varyng degrees of delustration. Thus with air at a temperature of 40 C. the filaments are sub stantially. completely delustred and are of dull or matt appearance, and the degree of delustration decreases as the temperature of the air is raised.

With air at a temperature of C. the filaments In performing the inventionwe preferably wind the filaments or threads up (continuously with their formation) with or without twisting, on apparatus located outside the evaporative atmosphere, though such winding may be performed within said atmosphere if so desired.

It isto be understood that the inventon is in no way limited to the particularexamples of execution described, which may be varied widely.

The filaments may be extruded either downwards or upwards into the spinning cell or metier casing, and the air current (which may be caused to pass either downwards or upwards through the metier casing or cell) may be heated or warmed thereinor prior toadmission thereto or both beforeand duringpassage through the celi or metier casing. Further, the filaments may be extruded in the same direction as or countercurrent to the air current.

flhe temperatures to be employed in the spinningfcells or metier casings may vary wth the boilingpoint of the solvents and precipitants used, the composition of the spinning solutions and the degree of, delustration it is desiredto producein the filaments or threads. Such tem peratures may be higher or lower than the boil- 7 ing point or points of the-solvent or solvents employed.

We have found that with the spinning cells or metier casings but we in no way limit ourselves to such temperatures.

Bymeans of the present, invention it is possible to obtain threads or filaments showing any desired degree of reduced lustre, from a completely delustred or matt appearance to a relatively high lustre, according to the proportion of precipitant present and the spinning conditions employed.

What we claim and desire to secure by Letters Patent i I action on the filaments in the natal state of the filaments.

2., Process forthe production of artificial filamerits presenting reduced lustre characterized in that solutions of cellulose acetate in volatile sol- 3. Method of producing artificial filaments presenting reduced lustre which comprises extruding intoa current of air heated to a temperature of between 40 and 80 C. a solution of cellulose acetate composed of 9'7 parts acetone,

23 parts Xylene, and 40 parts cellulose acetate.

4. Method of producing artificial filaments presentiz'ig reduced lustre which comprises extruding downwards through orificesinto a spinning cell asolution of cellulose acetate composed of 97 parts acetone, 23 parts xylene and 10 parts cellulose acetate, and causing a current of air heated to a temperature between 40 and 80 C. to pass upwards through said cell.

REGINALD WILLIAM PAYNE. ROBERT PIERCE ROBERTS. 

